Why doesn't my number have commas when I've formatted it to

Why doesn’t my number have commas when I’ve formatted it to.

public string? DFreeSpace3 => $"{DFreeSpace:n0}";

>Solution :

Your screenshot shows (not sure why you highlighted DFreeSpace3 though!)

public string? DUsedSpace { get; set; }

public string? DUsedSpace3 => $"{DUsedSpace:n0}";

Unfortunately you cannot format strings using standard numeric formats like this. I assume you’ve done something similar for the highlighted DFreeSpace3

Try using DUsedSpace2 instead which is a numeric type.

public string? DUsedSpace3 => $"{DUsedSpace1:n0}";